茶树鲜叶品质成分浸提方法比较及应用

代谢组学和系统生物学研究要求数据丰富、重复性好,简单易行、浸提效率高的样品前处理方法是获得较好的试验结果的关键步骤。比较了不同浸提剂（甲醇、乙醇和高氯酸）和不同研磨方法（球磨机和研钵研磨）对茶树叶片品质成分的浸提效果,结果表明,70%乙醇和70%甲醇对茶鲜叶氨基酸的浸提效率显著高于无水甲醇和无水乙醇,而对鲜叶茶多酚的浸提效率以100%乙醇和70%乙醇最好;3 mol·L^-1高氯酸对鲜叶氨基酸浸提效率最高,超过70%乙醇,但对茶多酚的浸提效率最低。优化出一种针对茶树鲜叶浸提的快速前处理方法（70%乙醇,球磨机研磨5 min）。对鲜叶经冷冻干燥和微波杀青处理后浸提的茶多酚和氨基酸含量进行了比较,发现冷冻干燥可以更好地保持茶树叶片中特征代谢产物成分。     

Polyphenol-Rich Extract of Fenugreek Seeds Protect Erythrocytes from Oxidative Damage

A polyphenol-rich extract from the seeds of fenugreek was evaluated for its protective effect against hydrogen peroxide(H₂O₂)-induced oxidation in normal and diabetic human erythrocytes (RBCs). RBCs, preincubated with increasing amounts of fenugreek seed extract and challenged with H₂O_2, were analyzed for hemolysis and lipid peroxidation. RBCs from diabetic subjects were more susceptible to oxidative hemolysis and lipid peroxidation than those from normal subjects. However preincubation with the polyphenol-rich extract significantly reduced the oxidative modifications in both the groups. The inhibition of lipid peroxidation was concentration-dependent up to 100 l of extract, which contained 0.75mM gallic acid equivalent (GAE) of phenolic compounds. These findings demonstrate the potent antioxidant properties of the fenugreek seeds.     

生态条件和种质因素对初烤烟叶次生代谢产物含量的影响

【目的】分析生态条件和种质因素对烤烟次生代谢产物含量的影响,为低危害烟叶生产提供理论依据。【方法】从贵州道真县、威宁县、盘县和天柱县采集K326、云烟87和贵烟1号3个烟草品种的C3F和B2F等级烟叶初烤样品,测定不同烟叶样本有机酸类、生物碱、多酚类、甾醇类物质等主要次生代谢产物含量,分析烤烟次生代谢产物含量的品种和地区差异性。【结果】同一地区3个品种(系)间的有机酸和生物碱含量差异不显著;道真县和盘县不同品种间烟叶多酚类物质含量、威宁县和盘县不同品种间烟叶甾醇类物质含量的差异均不显著;威宁县、天柱县不同品种间烟叶多酚类物质含量和道真县、天柱县不同品种间烟叶甾醇类物质含量的差异达显著或极显著水平。不同地区不同品种烟叶间的有机酸、生物碱、多酚和甾醇类物质含量差异明显,地区间烟叶主要次生代谢产物总含量的差别明显大于品种间。【结论】生态条件对烟叶次生代谢产物含量影响明显,种质因素对烟叶次生代谢产物含量影响较小。     

茶多酚对家兔C-BSA肾炎的治疗作用

考察了茶多酚对家兔C-BSA肾炎的治疗作用.结果表明:茶多酚大(306 mg/kg)、中(102 mg/kg)、小(34mg/kg)剂量组及地塞米松阳性对照组均能明显降低C-BSA肾炎模型免的尿蛋白和血清肌酐(P＜0.05或P＜0.01);减轻肾小球肿胀、细胞增生、血栓形成及白细胞浸润,修复肾小球病理改变;降低血清循环免疫复合物(P＜0.05).茶多酚大剂量的作用优于阳性对照药地塞米松(0.1 mg/kg,P＜0.05),并且大、小剂量间差异显著,有明显的剂量相关性.结果提示:茶多酚对家免C-BSA肾炎模型具有明显的疗效.     

Drought Tolerance in Cotton: Involvement of Non-enzymatic ROS-Scavenging Compounds

Compounds with reactive oxygen species (ROS)-scavenging ability were studied. High-performance liquid chromatography (HPLC) pattern of polyphenols, contents of proline and carotenoids, and antiradical (AR) capacity were determined. The malonyldialdehyde (MDA) level was also assessed. Tolerant and sensitive cotton genotypes were compared, grown in the Aegean region of Turkey at normal (field capacity) and limited (1/3 field capacity) water supply. Chlorogenic acid isomers and flavonoids were identified in HPLC pattern of polyphenols. At normal water supply, the tolerant genotype was distinguished by a higher content of all polyphenol types, higher proline, carotenoids and AR capacity and lower MDA level compared with the sensitive genotype. In plants subjected to water deficit, a decline of all polyphenol compounds, carotenoids and AR capacity was observed. However, this response was less pronounced in the tolerant than in the sensitive genotype, i.e. despite the stress conditions imposed, the tolerant plants maintained a more effective defence system. The data are corroborated by the weaker structural membrane damage in the drought-exposed tolerant vs. sensitive genotype, according to the MDA test. Hence, diverse chemical types are involved in the non-enzymatic ROS-scavenging system of cotton plants and can be related to the drought tolerance of this important crop.     

阿月浑子总酚含量与褐变关系研究

对阿月浑子不同器官、同一器官不同季节以及组培苗不同继代时期,植物体内总酚含量变化的研究。结果表明,阿月浑子富含多酚物质,叶片总酚含量最高,不适合组培试验;茎段含量较少,较适宜组培且春季取材最佳。组培苗随着继代次数的增加酚类物质总量也有所增加但是幅度不大。通过对褐化抑制剂的筛选,确定适合阿月浑子组培实验的抑制剂为PVP,其剂量以1.3~1.5 g/L较好。     

发酵型冬虫夏草菌茶的制备工艺研究

以绿茶为主要原料,配伍麦麸组成固体培养基,接种冬虫夏草菌进行固体发酵培养,加工冬虫夏草菌茶。结果显示,冬虫夏草菌在茶叶为主料添加麦麸的培养基上长势良好,通过L9（34）正交试验,以菌茶粗多糖含量为指标,筛选出培养基最优配方为茶叶60 g、麦麸30 g、碳酸钙0.4 g、蔗糖1.2 g。在料水比为5∶3（w·v-1）培养基上,接种12%（mL·g-1）冬虫夏草液体菌种,24℃培养12 d,55℃烘干,粉碎包装。成品菌茶汤为酒红色,香气清淡,无絮状物沉淀,pH值7.28,菌茶粗多糖含量为7.566%,茶多酚含量为1.488%。     

5种黔产药食两用植物总黄酮、多酚及多糖的含量测定

[目的]测定5种黔产药食两用植物中总黄酮、多酚及多糖的含量。[方法]选取茯苓、玉竹、天麻、木瓜和百合5种黔产药食两用植物为研究对象,运用紫外分光光度法测定5种植物乙醇提取液的主要抗氧化成分(总黄酮、多酚、多糖)的含量。[结果]茯苓的总黄酮、总多酚含量最高分别达到18.767 3和18.732 3 mg/g,而玉竹的总多糖含量最高达到154.437 6 mg/g。[结论]该方法测定了5种黔产药食两用植物中总黄酮、多酚及多糖的含量,为黔产植物的进一步开发利用提供了理论依据。     

新疆药用植物黑桑的抗氧化性

为寻找一种天然的抗氧化材料,以新疆药用植物黑桑的根、枝、叶和果实的乙醇提取物为材料,进行总多酚、总黄酮、抗氧化能力以及螯合 Fe2+测定。结果显示：果实(桑椹)提取物(EEMF)的总多酚含量(0.9438 mg· mL -1)以及总黄酮含量(0.1747 mg·mL -1)与叶提取物( EEML)、枝提取物( EEMB)和根提取物( EEMR)相比并不高,但 EEMF的抗氧化能力最强,其清除羟基自由基、DPPH 自由基能力分别达到96.46%,96.83%,抑制脂质体氧化能力达到71.14%;此外,EEMF螯合 Fe2+能力也强于其他3种。表明黑桑4个部位都具有良好的抗氧化能力,且果实最佳。     

黑茶发酵优势菌对茶多酚的生物转化研究

利用从茯砖茶中分离出的冠突散囊菌和从普洱茶中分离出的黑曲霉、根霉分别接种于以茶多酚作为唯一碳源的培养基中,进行单一菌株发酵,对发酵过程茶多酚类化合物的变化规律进行分析.结果表明,发酵期内,随着发酵时间延长,各发酵液的茶多酚总量显著降低,冠突散囊菌、黑曲霉、根霉发酵液中多酚分别降低38.9％、85.5％和92.1％;黄酮类总量在黑曲霉、根霉的作用下先下降后上升,冠突散囊菌则波动上升;各处理儿茶素总量均显著下降,其中酯型儿茶素含量直线下降,非酯型儿茶素和没食子酸的含量均先增加后减少.在黑曲霉、根霉作用下,茶黄素、茶红素含量显著减少,茶褐素含量增加.冠突散囊菌发酵液中茶黄素含量减少,茶红素含量增加,茶褐素含量基本不变.基于不同优势菌对茶多酚的转化在质和量上均有差异,有必要对其转化产物进行深入研究.